My bicycle has so many gears do I need to use them all?

You do not have to use all the gears on a bicycle. Think of it this way, if you bike has 21 or 24 or even 33 gears it is just gives you more options to find the gears you like. Let me give a quick breakdown to help simplify how to figure out where to find the different gears.

On the left side of the handle bar are typically 3 gears; 1,2,3. The smaller the number the easier the gear will be. That being said 1 is for climbing, 2 for cruising the flat land and 3 is for downhill going fast and showing off. The left 3 gears when shifted are major changes. On the right side of the handlebar you have 5, 6,7,8,9, or 10 gears. These gears are closer together. Meaning that when you shift it makes minor change. Think of these as fine tuning the feel of the gears.

So whether you have 21, 24, or 27, it is just made to give you options to make the bike ride the way you want to.